And for the hi-lo game what you say can't work because the house can't know if you will choose HI or LO at your next roll.
Am not sure about this! Some gamblers follow predictable patterns when placing bets or use well known strategies (martingale). Am not saying freebitcoin.in are doing this, but analysing the user's gameplay may give the casino an idea on what's the player's next bet is going to be.
What I don't get is why they need to change the server seed for each new bet! Given the reputation of freebitcoin.in, am sure there is a good reason for this.
The number of players is huge on Freebitco.in, it's way above most of casinos, so I think it would need a big amount of computing resources to give a specific server seed to each player and letting them changing it whenever they want. Moreover if someone guess his server seed by chance, he will be able to win all his rolls until the server seed rotates.